1. Field of the Invention
The present invention relates to a technique for creating an air stream between a functional module adapted to perform substrate positioning and/or testing after treatments and an ambient atmospheric carrying chamber, in a substrate processing apparatus including, for example, a vacuum processing vessel for providing a vacuum process to a substrate, for example, a semiconductor wafer and the ambient atmospheric carrying chamber adapted to carry the substrate in an ambient atmosphere.
2. Background Art
Among semiconductor manufacturing apparatuses, there is an apparatus for providing an etching process and/or film forming process to each substrate, such as a semiconductor wafer (hereinafter, referred to as a wafer) or a glass substrate for use in a flat panel, in a vacuum atmosphere. As such an apparatus, the so-called multi-chamber system is known, which includes a carrier port for placing a carrier thereon, a substrate carrying chamber, and a plurality of vacuum chambers each connected with the substrate carrying chamber.
To this system, various improvements have been added, taking into account enhancement of the throughput, downsizing and/or cost reduction, and, for example, apparatuses each including an ambient atmospheric carrying chamber connected with the carrier port and load lock chambers respectively provided between the ambient atmospheric chamber and the plurality of vacuum chambers (processing vessels) or apparatuses each including load lock chambers provided between a vacuum carrying chamber to which the plurality of the vacuum chambers are connected and the ambient atmospheric carrying chamber have been employed.
Generally, in an atmosphere in which substrates are placed and/or carried under ambient conditions, a fan filter unit (hereinafter, referred to as an FFU) is provided at a ceiling portion, from which cleaned air is fed to create a down flow, whereby particles to be generated from mechanical parts can be discharged so as to keep a cleaned atmosphere. For example, also in the ambient atmospheric carrying chamber, the FFU is provided at a ceiling portion and a discharging unit is provided at a bottom face in order to create a down flow with cleaned air.
Moreover, in the multi-chamber system, in order to place a substrate in each vacuum chamber, in a preset position and a predetermined orientation, it is necessary to provide an alignment module (orienter), which is a functional module adapted to determine an orientation and a central position of a substrate, for example, a wafer. For example, a configuration including such an orienter connected to the ambient atmospheric carrying chamber is currently employed.
The orienter is configured to include a rotary stage for placing a substrate thereon and a detecting means, for example a transmission-type sensor, for detecting the periphery of the substrate, both being provided in a housing. Also in this housing, an air stream of cleaned air is created by bringing in cleaned air of the ambient atmospheric carrying chamber from a transfer port, due to an intake effect by a fan, in order to discharge particles.
In each vacuum chamber connected to such a system, as in the case wherein a processing gas, such as an HBr gas or HCl gas, is introduced into the chamber and then changed into plasma so as to etch a polysilicon film formed on each wafer, by-products (silicon bromide, silicon chloride or the like) associated with such an etching process may tend to be attached to the wafer surface.
It has been found that upon carrying out such a wafer from each vacuum chamber, corrosive gases, such as hydrogen bromide, hydrogen chloride or the like, for example, may tend to be generated by reaction of silicon bromide, silicon chloride or the like as described above, with moisture in the atmosphere, and the corrosive gases may further tend to be reacted with ammonia existing in a trace amount in the atmosphere, so as to be changed into particles of ammonium bromide, ammonium chloride or the like and diffused in the carrying chamber.
As a result, the corrosive gases and particles diffused in the carrying chamber will also flow into the housing of the orienter, together with the cleaned air to be taken in from the ambient atmospheric carrying chamber. In the case where the corrosive gases flow into the housing, they will corrode metallic portions of the orienter. Alternatively, in the case where the particles flow into the housing, they will attach to the orienter. In particular, in the case where the particles attach to an optical system, light receiving signals are likely to be badly affected, thus making it difficult to detect accurate positions of the wafer periphery.
Patent Document (TOKUKAI No. 2004-281474, KOHO, Paragraph 0024, FIG. 1 and FIG. 2) describes a system including the FFU provided at a ceiling portion of the carrying apparatus for carrying wafers between respective devices during a semiconductor manufacturing process. However, this reference does not refer to the above issue.